A flame retarder is an agent added to a flammable material (e.g. plastic, rubber, cellulose, paper, wood, and the likes) to make it non-flammable or no flame expandable. In recent decades, flame retarders have been applied in various fields such as the chemical industry or in various products such as electronic products. In general, flame retarders contain halogen. However, global areas, such as the Europe Union on Jul. 1, 2006, have declared restrictions on the use of certain hazardous substances in electrical and electronic equipment; so-called RoHS, wherein the halogenated flame retarder cannot be applied to 3C products (e.g. substrate or plastic housing in computers, televisions, and the likes). Accordingly, a competitive non-halogen flame retarder which is highly efficient, meeting the restrictions such as no halogen, is called-for.